1. Field of the Invention
The present invention generally relates to surgical instruments, and more particularly to an endoscopic instrument having improved means for removably connecting the actuation rod.
2. Description of the Prior Art
Endoscopic medical procedures for surgery and diagnosis are widely practiced throughout the world today and their acceptance is growing rapidly due to the associated advantages relating to reduced trauma and hospitalization time. These procedures are generally referred to as "minimally invasive surgery". Various types of endoscopic surgical instruments are known in the art. These instruments generally include a slender tube containing a push rod which is axially movable within the tube by means of a manual actuator. One or more end effector mechanisms are coupled to the distal ends of the tube and the push rod so that axial movement of the push rod is translated to rotational or pivotal movement of the end effector mechanisms. End effectors may take the form of scissors, grippers, cutting jaws, forceps, and the like.
Traditionally endoscopic instruments have been manufactured as reusable devices which can be cleaned and sterilized following a procedure, or as disposable devices which are discarded after a single surgical procedure. With disposable devices cleaning is not an issue since they are not reused or resterilized. One of the most common problem is that the end effectors often get dull from use and must be discarded. The end effectors of reusable instruments must always be cleaned and properly sterilized after each surgical procedure. Although techniques such as steam sterilization have been widely used, they are often inadequate to reach all of the blood and tissue residues that can enter an instrument during a surgical procedure. Endoscopic instruments are often constructed with an elongated tubular body housing and small precisioned mechanical parts. Microscopic pockets of blood and tissue, which can infiltrate the body of the endoscopic instrument, are often left on the instrument even after completion of accepted sterilization procedures. Frequently this is because the instrument cannot be adequately disassembled. This creates a concern of infectious disease and the potential of cross-contamination to patients and health care professionals alike. In order to insure complete sterization of a surgical instrument, the instrument must be capable of easy disassembling into its major components. This insures that all surfaces of the instrument are exposed to the particular sterilization medium and any concern that the instrument is not thoroughly sterilized is thereby eliminated.
The advantages of disposable, one time use of these instruments is often compromised by the high cost per instrument and the environmental problems associated with medical waste disposal. The benefits of endoscopic instruments, that are easy to use and which can be assembled and disassembled with a minimum of wasted time due to an economy of parts, have long been recognized. Especially important is an endoscopic instrument having end effector mechanisms which can be easily disconnected for discarding, because it is this part that most often becomes worn, dull and requires the greatest degree of cleaning care.
An example of a surgical instrument that depicts a removable front end is shown in U.S. Pat. No. 5,718,714 issued to Livneh on Feb. 17, 1998. Livneh teaches of a handle assembly having a releasable coupling member which releasably connects with the front end member. The front end member is capable of rotation and the rotation can also be inhibited by a locking member. This patent discloses the advantages from being able to use a variety working front end elements. The proximal end of the front end shaft is seated within a rigid slot. Entrance to the slot is by manually turning a cap assembly that opens up access to the slot therein.
U.S. Pat. No. 5,618,308 issued to Holmes et al., discloses a simple surgical instrument which seats the inner rod within the thumb loop housing by means of a rigid slot. Several steps are required to remove the connecting member from the housing.
U.S. Pat. No. 5,618,303 issued to Marlow et al., discloses a knurled knob for easy rotation of the actuator rod. He also teaches the removal of only the working part of the instrument, This is the part of the instrument that is most likely exposed to contamination and also the hardest to clean. The mechanism for connecting the working end to the shaft can often be almost as difficult to clean as the original working member.
U.S. Pat. Nos. 5,782,748 and 5,746,759 are presented as examples of the prior art seeking to disclose detachable shaft connections.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.